Process for preparing mixed lithium-calcium soap thickened greases

ABSTRACT

This invention concerns a novel process for preparing mixed alkali metal-alkaline earth metal soap thickened greases of depressed yield by a one-stop, non-melt process in which the temperature does not exceed the melting point of the alkaline earth metal soap contained in the grease during the entire grease manufacturing cycle. This procedure is especially useful in the preparation of water-resistant greases.

Q Umted States Patent 11 1 1111 3,891,564 Carley et a1. June 24, 1975[54] PROCESS FOR PREPARING MIXED 2.929,?32 3/1960 Sproule et al 252 40L|THIUM CALC|UM SOAP THICKENED 2,959,548 1 1/1960 OHalloran et a1.252/40 GREASES 3,133,020 5/1964 Scott .1 252/405 3,139,405 6/1964 Farmeret a1. 252/405 [75] Inventors; Don A, Carley, Nederland; Fred T,3,158,574 11/1964 Greenwood et al 252/4017 Crookshank, p Arthur, both f3,171,812 3/1965 Horth et a1. 252/4045 3,242,082 3/1966 Badgett et a1252/40 3,801,506 4/1974 Cross et a1. 252/40 [73] Assignee: Texaco Inc.,New York, NY.

22 n Feb 14, 1972 Primary Examiner-Delbert E. Gantz Assistant Examinerl.Vaughn App! 226304 Attorney, Agent, or Firm--T. l-l. Whaley; C. G.Ries',

Bernard Marlowe [52] US. Cl. 252/40; 252/41; 252/52 A [51] Int. Cl.....Cl0m 5/16;C10m 5/14', C10m 5/12 [58] Field of Search 252/40, 33.6, 40.5,40.7, [57] ABSTRACT 252 5 5 R, 39 37 7 4 52 A This invention concerns anovel process for preparing mixed alkali metal-alkaline earth metal soapthickened 5 References m greases of depressed yield by a one-stop.non-melt UNITED STATES PATENTS process in which the temperature does notexceed the melting point of the alkaline earth metal soap con- ?gggigt;""'"""""' 2 tained in the grease during the entire grease manufac-2475589 7/1949 Bondi ....:I. II II. III. 252/401 F proceiure especanyusefu' 2:s45:190 3/1951 Bondi............ 252/407 Preparatlo" ofwaterreslstam greases- 2,588,556 3 1952 Moore et a1. 252 40.5 2,831,8124/1958 North 25 2/40 5 Clams Drawmgs 1 PROCESS FOR PREPARING MIXEDLITHIUM-CALCIUM SOAP TI-IICKENED GREASES BACKGROUND OF INVENTION Theprolonged contact of greases containing hydrophilic components with anaqueous environment is usually detrimental to the grease. The reason forthis is that hydrophilic components are attacked by water, especially atelevated temperatures. When the hydrophilic agent is the gelling agent,such as a lithium soap, sodium soap or a mixture of these alkali metalsoaps with alkaline earth soaps, attack by water is particularly acutebecause these soaps are emulsifying agents and tend to leach out. As aresult of this extraction or leaching that alkali metal soaps undergo,the structure of the grease is degraded and, because of deficientlubrication, the part to be protected can be damaged or can fail.

Another area of concern caused by the poor resistance of greases to theattack of water is the field of water pollution. For example, facilitiessuch as foundries or steel mills which utilize large amounts oflubricants in processes requiring the use of large quantities of waterfor cooling or washing, frequently discharge huge quantities of soaps orother grease components into the waterways which cause undesirablechanges in the life cycle and appearance of the waterways. While it issometimes possible to remove the grease pollutants from the waterways,it almost always is costly and can be avoided by use of prophylacticmethods; in this instance, utilizing greases possessing good waterresistance.

Recently a grease formulation comprising a mixed alkaline earth metalsoap-alkali metal soap grease was prepared which incorporated lithiumand calcium soaps as gelling agents and certain polyoxylalkylatedderivatives to further enhance the greases normal resistance to water.These novel greases were disclosed and claimed in co-pending Ser. No.161,993 filed July l2, l97l, in the United States Patent Office. Whilethese formulations of mixed soap greases possessed excellent resistanceto water, and excellent appearance among other attributes, their methodof preparation left something to be desired. That is, the preparativeprocess requires a relatively tedious and complex twostep saponificationfor each soap. For example, in the preparation of a calcium-lithium soapbased grease, the calcium soap is first made from l2hydroxystearic acidand calcium hydroxide. Then the lithium soap is prepared by saponifyingl2-hydroxystearic acid and/or methyl-IZ-hydroxystearic acid with apremixed lithium hydroxide solution. Previous experimental work on mixedlithium-calcium soap greases indicate that the two-step saponificationis necessary to obtain a grease with a satisfactory texture andappearance. Surprisingly enough good texture and appearance of a greaseis a necessity in the successful marketing of a commercially acceptableproduct.

In view of the difficulties encountered in the attempts to produce mixedalkaline earth metal-alkali metal soap greases (such as calcium-lithiumsoap thickened greases) possessing good texture and good appearancethrough a onestep saponification procedure, it was quite unexpected andsurprising to discover that a suitable mixed grease having satisfactorytexture and appearance could be prepared in depressed yield primarily byutilizing reaction temperatures below the melting point of the alkalineearth metal soap or soaps contained in the mixed soap grease. When thiscritical temperature employed during manufacture is combined with aone-step saponification and utilizes a critical ratio of oil to fat inthe charge especially useful mixed soap thickened greases are produced.

Thus, it is the broad object of this invention to provide a method forpreparing alkaline earth metal soapalkali metal soap thickened greaseswhich are equally recalcitrant to the attack by water as are comparablegreases made by the two-step saponifications of the prior art.

Other objects will suggest themselves to those skilled in thelubrication art after a perusal of this disclosure.

DETAILED DESCRIPTION OF THE INVENTION In the broad practice of thisinvention, a mixture of alkaline earth metal soap-alkali metal soapthickened grease of depressed yield and possessing substantiallyincreased resistance to water is prepared by a one-step, non-meltsaponification of the saponifiable fats present while keeping thetemperature of the grease during the entire manufacturing cycle belowthe melting point of the alkaline earth metal soap or soaps contained inthe finished grease. As in the case in the conventional two-stepsaponification procedure, the formulation, including additives andgrease adjuvants is virtually unchanged.

In the most favored contemplated practice, a grease thickened by amixture of lithium soap-calcium soap having comparable improvedresistance to water as to conventional greases gelled by mixtures ofcalcium soap and lithium soap is prepared by concurrent and in situsaponification of the calcium and lithium fatty components keeping themaximum temperature below the melting point of the calcium soap not onlyduring saponification but throughout the entire grease manufacturecycle. Of secondary but significant importance is controlling the ratioof the oil present to the fat employed.

In order to aid in the understanding of the inventive concept, thefollowing additional disclosure is submitted. Unless otherwiseindicated, all parts and percentages are by weight rather than by volumeand all temperatures are in degrees F rather than degrees C.

A. Alkoxylated additives imparting water-resistance to greases. Theseare selected from the group consisting of:

1. Polymeric Alkoxylated Derivatives of Alcohols.* Alcohols as usedherein not only refer to aliphatic compounds containing at least onefree-hydroxyl group but which as can be seen from supra also includesdiols, trials and polyols.

These additives, which are used to impart increased water-resistance togreases thickened with alkali metal soaps, are known in the patent ortechnical literature. See, for example, the preparation of a copolymerof polyoxyethylene and polyoxypropylene glycol having a molecular weightfrom 300 to 15,000 as disclosed by Toussaint et al in US. Pat. No.2,425,845 and Roberts et al in ()5. Pat No. 2,425,755, both assigned toCarbide & Carbon Chemicals Corp. These novel grease additives may beobtained among other preparative methods using the aforementionedprocess of Toussaint et al and Robert et al, by the alkaline catalyzedreaction in a substantially anhydrous environment of a mixture ofethylene and 1,2 propylene oxides with alcohols, diols and/or polyols,or their mixtures, at temperatures ranging from about C to C. Typicalalcohols,

diols and polyols include methanol, n-butanol, noctanol, ethyleneglycol. propylene glycol, glycerol and sorbitol, among others. Theaverage molecular weights as measured by the ebullioscopic method orcalculated from viscosity measurements or acetyl values are betweenabout 300 to about 15,000. The favored copolymers usually contain fromabout 50 to 75 parts by weight of propoxy groups, and from about 25 to50 parts by weight of ethoxy groups and have an average molecular weightof from about 1500 to about 10,000. One of the preferred copolymers issold by Retzoloff Chemical Company of Houston, Texas, as DPB-15. 1tcontains about 75 to 90 parts by weight of propoxy groups and from about25 to 10 parts by weight of ethoxy groups.

The novel copolymer additives are employed in an amount effective tosubstantially increase the resistance of the alkali metal soap-alkalineearth metal soap-thickened grease to the attack by water. This amountwill vary according to the additive employed, the degree of protectionsought, the alkali metal soap contained in the grease, etc. However,when lithiumcalcium soaps are used to thicken a mineral oil base and thepreferred copolymers are derived from alkoxylation of di-, tri-, orpolyhydroxylated compounds, from about 0.1 parts by weight to 5.0 partsby weight of copolymer per hundred parts by weight of the finishedgrease represents the extremes of the polymer content. A more usefulrange of about 0.1 to 0.6 parts by weight of copolymer produces greaseswhich have good properties and consistently pass water-resistance tests,and for this reason are preferred.

2. Alkoxylated Adducts of Alkylated Phenols.

The second class of additives employed to provide improvedwater-resistance to said greases, particularly calcium-lithiumsoap-thickened greases comprises alkylene oxide adducts of alkylatedphenols. The favored alkylene oxides are ethylene oxide, propylene oxideand their mixtures. A favored group within the class are alkylatedphenols wherein the alkyl group contains 5 to 15 carbon atoms, whichhave from 2 to 50 alkoxylate groups attached to the molecule. Thepreferred additives within this class are ethoxylated phenols whosealkyl groups contain 6 to 10 carbon atoms and an average of 5 toethoxylate groups per molecule.

Two of the preferred ethoxylated alkylated phenols are commerciallyavailable. One of these is a nonyl phenol ethoxylated with an average of9.5 moles of ethylene oxide per mole of nonyl phenol. The secondphenolic adduct which is preferred is supplied by the Retzloff ChemicalCompany of Houston, Texas, and is designated as DRB-203.*

The properties of this additive are: Viscosity at 77F 575: 50 ctks,Form-liquid, Specific Gravity 1.02 at 60F, Pour Point, F -Below 5F, MoleWt. 6000-8000.

3. Mixed Alkoxylated Products of Alkylene Diamines.

P (ocn cn (ocn cnh 11(0c1i cH -(ocn cah,

The third class of additives which impart substantially improvedwater-resistance to greases refers to products formed by initiallyadding an alkylene oxide such as ethylene or propylene oxide to analkylene diamine such as ethylene diamine (H N-CH C- H H N) to give thesymmetrical tetrapropoxylated derivative followed by subsequentoxyethylation to a structure shown below:

CH CH wherein x an integer ranging from 6 to 16.

These condensates are also available commercially from the PetroliteCompany of Houston, Texas. A favored additive is referred to by themanufacturer at Tretolite Additive A-3089" whose active componentsstructure appears above.

B. Lubricating Oils.

The lubricating oils employed as the base fluids in this invention ofprime interest are the natural (mineral) oils, or mixtures of one ormore of these oils. The mineral oils which can be used are those ofparaffinic, naphthenic, asphaltic or paraffinic-asphaltic type derivedfrom crude oils by refining processes including distillation, crackingand/or polymerization. These oils will have a gravity (APl) of about 10to 35, a viscosity within the range of 100 to 2000 SUS at 100F and flashpoints within the range of about 275F to 650F. Generally a viscosity offrom about 500 to 1400 SUS at 100F is favored.

The lubricating base oils preferred for the water resistant greaseformulations are mineral oils of the paraffinic type having SUSviscosities at 210F in the range of about to and flash points in therange of about 450F to 600F. The above oils are preferred as bases forgreases because they consistently produce greases having generally goodcharacteristics and enhanced resistance to water.

C. Ratio of Oil to Fat.

For reasons presently unknown, the ratio of oil to fat plays animportant role in the novel one-step saponification process to formmixtures of calcium and lithium soaps. Through experimentation it hasbeen found that ratios of oil to fat ranging from 2:1 to 4:1 usuallygive good results but higher or lower ratios of oil to fat presentproblems. For example, higher ratios of 5:1 to 7:1 and higher cause poorappearance due to nonhomogenity, while lower ratios cause the formationof very heavy soap base which could overload the agitation meansemployed and unduly extend the processing cycle.

D. Optional Grease Adjuvants.

The term adjuvants" as used throughout this disclosure is used todescribe any materials or agents (excluding the inventive additivesimparting water-resistance and the alkali metal and alkaline earth metalsoapthickeners) which are incorporated into the grease formulation toenhance desirable properties or to elimi' nate or minimize deleteriousproperties. These adjuvants can be of diverse structure or origin andare typified by the following: extreme pressure (E.P.) agents such asthe metallic naphthenates and sulfurized sperm oil, fillers such as themetal oxides, oxidation inhibitors including phenyl-beta-naphthylamineand the diphenyl amines, corrosion inhibitors including alkali metalnitrites, and stabilizers such as the fatty acid esters. When theseoptional adjuvants are employed they are used in minor amounts, seldomtotaling more than percent by weight of the finished grease. Moreusually these adjuvants comprise from about 0.5 to 7.0 parts by weightper hundred parts by weight of finished grease. Ordinarily, theseadjuvants are added at the expense of the oil base, most often duringthe cooling step that takes place during the finishing of greases.

E. Mixed Alkali Metal Soaps and Alkaline Earth Metal Soaps.

The soap-thickeners of prime interest in the formulation of thewater-resistance greases of this invention broadly include mixtures ofalkali metal soaps and alkaline earth metal soaps. More narrowly theprocess relates to greases thickened by calcium and lithium soapmixtures. These latter greases are particularly useful because whencombined with the additives disclosed in Ser. No. 161,993 not only dothe greases exhibit good general lubrication properties, but they alsoexhibit far superior water resistance.

As will be disclosd infra, one of the salient advantages of the subjectprocess is that it permits one-step saponification of the calciumsoap-lithium soap mixture without compromising the general properties ofthe grease or its appearance. In short, this is accomplished byconcurrently saponifying both the strongly alkaline form of both metalswhich can be saponified with saponifiable material. The terms stronglyalkaline metal material or strongly alkaline metallic agent refers tobasic forms of alkaline earth metals and alkali metals such as theirhydroxides, oxides, alkoxides and the like and/or mixtures of thesematerials. As indicated previously in order to obtain the advantages ofthis invention at least one basic alkaline earth material and at leastone basic alkali material must be employed. Illustrative basic alkalineearth materials include alkaline earth hydroxides, alkaline earth oxidesamong others. Preferred alkaline earth materials are calcium hydroxide,calcium oxide or mixtures of these calcium materials. Illustrative basicalkali metal materials include lithium hydroxide, sodium hydroxide,sodium methoxide as well as mixtures of these basic alkali metalmaterials. The preferred basic alkali metal material is lithiumhydroxide. The term saponifiable material refers to fatty acids andhydroxy-substituted fatty acids and their esters containing 1 to 4carbon atoms. Especially useful are those saponifiable materialscontaining from about 12 to 32 carbon atoms per molecule. Also includedare glycerides or hydroxylated glycerides. Suitable saponifiablematerials include the following illustrative materials:l2-hydroxystearic acid, stearic acid, hydrogenated castor oil, myristicacid and the like.

The preferred saponifiable materials in the order of preference arel2-hydroxystearic acid, stearic acid, hydrogenated castor oil and/ortheir mixtures. in the most favored composition, the saponifiablematerial is l2- hydroxystearic acid.

F. Novel Process for Preparing the Novel Low Water Absorbing Greases ofthis invention.

The novel process requires the temperature of the grease to be keptunder the melting point of the alkaline earth metal soap or soaps usedduring the manufacturing cycle. In the continuous units temperatures aremost conveniently controlled by the temperatures maintained in thereactor jacket, while in the case of batch precessed greases. adjustingthe kettle jacket temperature affords the most practical means ofcontrolling the temperature of the grease. Wherecalcium-l2-hydroxystearate is the alkaline earth metal of the mixed soapthis requires maintaining the temperature below 293F. throughout theentire preparative process.

G. Consistency (Grades) of Greases Produced Using the Novel ProcessBecause of their overall suitability as a lubricant in manyapplications, the mixed alkaline earth metalalkali metal soap thickenedgreases can be manufactured in at least three consistencies as definedby National Lubricating Grease Institute (N.L.G.l.) to be 0, 1 and 2described in ASTM Method D-2l7 for Cone Penetration of LubricatingGreases. Adjusting the oil and additive content will permit themanufacture of various other grades of greases. For example, a typicalgrease of the NLG] 0 grade would be composed of 7 parts by weight oftotal soap, 88 parts by weight of oil and 5 parts by weight ofadditives. A typical grease of the NLGI 1 grade would be composed of l2parts by weight of total soap, 83 parts by weight of oil and 5 parts byweight of additives; while a typical grease of the NLGI 2 grade would becomposed of l6 parts by weight of total soap, 79 parts by weight of oiland 5 parts by weight of additives. Preparation of the other NLGI gradesof grease can be readily accomplished by further adjustments in theconcentrations of soap and oil present in the grease.

EXAMPLE 1 Preparation of a Lithium-Calcium Soap-Thickened Grease HavingBoth Enhanced Water Resistance and Good Appearance Using Concurrent InSitu Saponification and Control of Temperature of the Reaction MixtureI. A grease kettle equipped with heating, cooling and stirring means ischarged with 156 pounds of lithium hydroxide monohydrate and 780 pounds(97 gallons) of water. The aqueous alkali mixture is stirred for about15 minutes and 3200 pounds of mineral oil base A*, 1600 pounds ofl2-hydroxystearic acid and 74 pounds of hydrated lime are added withcontinuous stirring.

Mineral oil base A used in this example and subsequent examples has thefollowing properties:

API Gravity 26.5 Viscosity SUS at 100?. l20l Viscosity SUS at 210F. 93.8Flash Point (COC) 520"F. Pour Point 0F.

ll. The stirred charge is then heated to between 180F. to 200F. tosaponify the mixedlithium-calcium soap. The heating of the stirredsaponification mixture is controlled carefully to assure that no part ofthe mixture exceeds 293F. during the batch cycle.

111. At the end of the saponification step the aqueous mixed soapsolution is conditioned by heating to 270F. to 275F. It is stirred at270F. to 275F. for 3 to 4 hours or until soap base has a very heavy,smooth texture and translucent appearance.

1V. At the end of this time an additional 439] pounds (589 gallons) ofmineral oil base A* is added at a rate at which it will blend insmoothly (about 1 gallon per minute).

V. When the above oil addition is completed, 562 pounds (76.7 gallons)of base oil 8* is added at a blendable rate (at about 3 gallons perminute).

Vl. After the addition of base oil B*, the temperature of the stirredmixture is maintained between 180 and 220F. and the followingadditives** are blended in with stirring:

215 pounds of lead naphthenate 142 pounds of lead diamyldithiocarbamate74 pounds of antimony dialkyldithiocarbamate 72 pounds of copolymer ofpolyoxyethylene and polyoxypropylene 145 pounds of a residuum oil****3,324 pounds of base oil A 260 pounds of base oil B "Mineral oil base Bused in this example and subsequent examples has the followingproperties:

A?! Gravity 29.2 Viscosity SUS at 100F 335 Viscosity SUS at 210F 54.3Flash Point (COC) 450F. Pour Point F.

"The quantities of additives blended in represent total amountscorrected to conform to specifications after testing.

""The copolymer has the following properties:

Vll. After the addition of the additives including additional oil iscomplete, stirring is continued at about 195F. for 1 hour to insurehomogeneity, a sample is taken for testing. As the data in examples 1 to3 (presented in Table l) indicate, not only are the general physicalproperties including water resistance good, but the appearance of thefinished grease is smooth, not grainy as is the case in the preparationswhere the critical jacket temperature is not maintained and oil to fatratio is greater than 4:1.

Equally suitable greases can be prepared by substituting eitherhydrogenated castor or methyl-l2- hydroxystearate for l2-hydroxystearicacid in the above process.

EXAMPLE 2 Preparation of a Lithium-Calcium Soap-Thickened Grease HavingBoth Enhanced Water Resistance and Good Lubricating Properties but PoorAppearance In this run the same reactants and general reaction procedureare employed as in Example 1 except that the jacket temperature isallowed to exceed the melting point of the calcium l2-hydroxystearatewhich is 293F. The procedure is as follows:

1. A grease kettle equipped with heating, cooling and stirring means ischarged with 4.6 pounds of lithium hydroxide monohydrate and 23.4 poundsof water. The aqueous alkali mixture is stirred for about 15 minutes and160.4 pounds of mineral oil base A, 47.32 pounds of l2-hydroxystearicacid and 2.25 pounds of hydrated lime are added with continuousstirring.

11. The stirred charge is then heated to between 180F. to 200F. tosaponify the mixed lithium-calcium soap. During this heating period thekettle jacket reaches 350F. and the temperature of the saponificationmixture touching the kettle wall is between 293 and 350F. to produce abulk temperature between 180 to 200F.

111. At the end of the saponification step the aqueous mixed soapsolution is conditioned by heating to 270F. During the heating periodthe kettle jacket reached 350F. and the temperature of the mixturetouching the kettle wall is between 293 and 350F. to produce a bulktemperature between 270 to 275F. The batch is stirred at 270 to 275F.for 3 to 4 hours.

IV. At the end of this time an additional 104.6 pounds of mineral oilbase A is added at a rate at which it will blend in smoothly (about 1.5lbs. per minute), and the mixture is allowed to cool to 180 to 220F.

V. When the above oil addition is completed, 25.25 pounds of base oil Bis added at a blendable rate.

Vl. After the addition of base oil 8, the temperature of the stirredmixture is maintained between 180 and 220F. and the following additivesare blended in with stirring:

5.25 pounds of lead naphthenate 3.50 pounds of leaddiamyldithiocarbamate 1.75 pounds of antimony dialkyldithiocarbamate1.75 pounds of a copolymer of polyoxyethylene and polyoxypropylene 3.50pounds of a residuum oil Vll. After the addition of the additives iscomplete the batch is stirred for an additional 30 minutes at 180-220F.to insure homogenity and a sample taken for testing. Although theresultant grease exhibits good test characteristics, its texture andappearance are at comparable to the smooth, buttery texture of thegrease of Example 1. The test data appears in Table 1.

EXAMPLE 3 Preparation of Another Lithium-Calcium Soap Thickened GreaseHaving Poor Appearance in this run the procedure of Example 1 isfollowed but the oil to fat ratio is outside (in this instance higher)than the recommended 2:1 to 4:1 weight range. The procedure used appearsbelow:

1. A grease kettle equipped with heating, cooling and stirring means ischarged with 1.58 pounds of lithium hydroxide monohydrate and 7.9 poundsof water. The aqueous alkali mixture is stirred for about 15 minutes and82.6 pounds of mineral oil base A, 16.22 pounds of l2-hydroxystearicacid and 0.76 pounds of hydrated lime are added with continuousstirring.

II. The stirred charge is then heated to between l80F to 200F tosaponify the mixed lithium-calcium soap. The heating of the stirredsaponification mixture is controlled carefully to assure that no part ofthe mixture exceeds 293F during the batch cycle.

lll. At the end of the spaonification step the aqueous mixed soapsolution is conditioned by heatingto 270F to 275F. it is stirred at 270Fto 275F for 3 to 4 hours.

IV. At the end of this time an additional 9.4 pounds of mineral oil baseA is added at a rate at which it will blend in smoothly (about 0.5 lbs.per minute), and the mixture is allowed to cool to [80F to 220F;

added to the stirred charge. During the addition and after the additionthe consistency of the batch increases substantially and stirringbecomes very difficult. As a consequence the batch is not completelyhomogeneous and requires an inordinately long time to heat up. Samplesof the grease batch when the grease is finally prepared containsundispersed soap lumps and both the grease appearance and properties arepoor. Further the batch cycle (preparation time) is impractically longand for these reasons greases prepared with oil to fat weight ratioslower than 2:] are not practical to prepare.

TABLE 1 Example 1 Example 2 Example 3 Composition:

Lithium l2-Hydroxystearate 9.6 9.3 9.3 Calcium l2-Hydroxystearate 4.74.7 4.7 Mineral Base Oil A 75.5 75.8 75.8 Mineral Base Oil B 5.7 5.7 5.7Lead Diamyldithiocarbamate [.0 1.0 L Antimony Dialkyldithiocarbamate 0.50.5 0.5 Copolymer of polyoxyethylene and polyoxypropylene 0.5 0.5 0.5Residuum Oil 1.0 L0 1.0 Lead Naphthenate L L5 [.5

Total |00.0 100.0 I000 Tests;

Penetration at 77F Worked 60 strokes 332 333 322 Grease Water AbsorptionTest X Water Absorbed 100 90 85 Original Penetration 305 305 298Penetration of Emulsion 287 287 294 ASTM D-l264 Water washout 1 Loss at[00F L4 3.5 2.7

Z Loss at |75F 2.2 3.7 3.8

V. When the above oil addition is completed, 6.8 pounds of base oil B isadded at a blendable rate.

Vl. After the addition of base oil, the temperature of the stirredmixture is maintained between 180F and 220"] and the following additivesare blended in with stirring:

l.8 pounds of lead naphthenate 1.2 pounds of lead diamyldithiocarbamate0.6 pounds of antimony dialkyldithiocarbamate 0.6 pounds of a copolymerof polyoxyethylene and polyoxypropylene and polyoxypropylene 1.2 poundsof a residuum oil Vll. After the addition of the additives is completethe batch is stirred for an additional minutes at l80-220F to insurehomogenity and a sample is taken for testing. Although the greaseprepared in this example exhibits good test characteristics, its textureis mealy and its appearance is unacceptable.

Inasmuch as the heating temperatures are within the recommended limits,the poor texture and appearance can be attributed to the 5 to 1 weightratio of the oil to fat used in the run.

EXAMPLE 4 Preparation of Another Lithium-Calcium Soap Thickened GreaseHaving Poor Appearance In this run a lower oil to fat ratio than therecommended 22] weight ratio is employed. Again the same procedure andthe same components used in the grease prepared in Example I areemployed.

To the grease kettle is charged 4.60 lbs. of lithium hydroxide and 23.4lbs. water. After stirring for 15 minutes, 47.32 lbs. of Mineral OilBase A, 47.32 lbs. of 12- hydroxystearic acid and 2.25 lbs. of hydratedlime are As the preceding examples and discussions have indicated, thenovel preparation process of this invention offers several advantagesover processes used to prepare comparable greases thickened by a mixtureof both alkaline earth metal soaps and alkali metal soaps. For example,not only does this one-step saponification procedure reduce the timeneeded for the manufacturing cycle compared to processes employing twoseparate saponification steps but the resultant grease contains moresoap than greases having comparable properties. These depressed yieldgreases will be more resistant to deterioration in service particularlyunder wet conditions.

Further, the above advantages are achieved without significantlyaffecting lubricating properties or the appearance of the grease.Surprisingly enough the latter factor (appearance) which is a veryimportant consideration in commercial acceptance of a grease, is muchsuperior compared to greases formerly prepared by simuitaneoussaponification of the mixed soaps at tempertures exceeding the meltingpoint of the alkaline earth soap contained in the grease. in addition,the novel process is equally applicable to both batch or continuousoperation.

Finally, the invention process is relatively flexible insofar as themineral base oil, the fatty acids and alkaline materials that may beemployed. However, the metes and bounds of this invention are bestascertained by an examination of the claims which follow, read inconjuction with the preceding specification.

What is claimed is:

l. A nonmelt process for preparing mineral oil-based greases combininggood lubrication properties, good resistance to water and a smoothnongrainy appear- 1 1 12 ance, said greases being thickened by a mixtureof calexceeding the melting point of the calcium and cium soaps andlithium soaps, formed in situ through lithium soap until the calcium andlithium soap the saponification of a saponifiable fatty material withare formed; a mixture of calcium hydroxide and lithium hydroxide 3.adding from 5.0 to 0. 1 parts by weight ofa copolywith the provisos 5mer of polyoxyethylene and poly-1,2-oxypropylene a. that during the insitu saponification step between having a molecular weight of from about2300 to the fatty materials and the calcium and lithium hy- 2500 to saidheated saponification mixture, and droxide materials said saponificationalways takes 4. adding to the heated mixture of mineral oil, calplace inthe presence of excess mineral oil of lubricium and lithium soaps from7.0 to 0.5 parts by eating viscosity, the excess of oil to fat not to exweight of grease adjuvants while maintaining the ceed a ratio of 2:] to4:] and temperature of the saponification mixture below b. that duringsaid saponification step and throughout the elting POinl 0f aid lith umand Calcium the entire preparative process the saponification p WhileOptionally adding Sufficient mineral temperature shall not exceed thelti point f oil to said saponification mixture until a grease of thecalcium and lithium soaps formed during the the desired consistencyhaving good lubrication saponification process, said non-melt processconp p i g resistance Wale! and g 8P- sisting essentially of: pearanceis produced. 1. admixing from about 4,5 parts b i h t 2. The process ofclaim 1 wherein the saponification parts by weight of the saponifiablefatty material temperature ranges from 230F to 293F. with from about 0.1to L6 parts by weight of cal- 20 3. The process of claim 1 wherein thesaponifiable cium hydroxide and from about 0.1 to 1.3 parts material isstearic acid. by weight of basic lithium hydroxide materials in 4. Theprocess of claim 1 wherein the saponifiable the presence of sufficientmineral oil to maintain fatty material is l2-hydroxystearic acid. theratio of said mineral oil to said fatty materials 5. The pr ess of laim1 wherein he ponifiable ranging from 2:l to 4:]. and to form asaponififatty material is a mixture of stearic acid and 12- cationmixture; hydroxystearic acid. 2. heating said saponification mixture upto but not a

1. A NONMELT PROCESS FOR PREPARING MINERAL OIL-BASED GREASES COMBININGGOOD LUBRICATION PROPERTIES, GOOD RESISTANCE TO WATER AND A SMOOTHNONGRAINY APPEARANCE, SAID GREASES BEING THICKENED BY A MIXTURE OFCALCIUM SOAPS AND LITHIUM SOAPS, FORMED IN SITU THROUGH THESAPONIFICATION OF A SOPONIFIABLE FATTY MATERIAL WITH A MIXTURE OFCALCIUM HYDROXIDE AND LITHIUM HYDROXIDE WITH THE PROVISOS A. THAT DURINGTHE IN SITU SAPONIFICATION STEP BETWEEN THE FATTY MATERIALS AND THECALCIUM AND LITHIUM HYDROXIDE MATERIALS AND THE CALCIUM AND LITHIUMHYDROXIDE PRESENCE OF EXCESS MINERAL OIL OF LUBRICATING VISCOSITY, THEEXCESS OF OIL TO FAT NOT EXCEED A RATIO OF 2:1 TO 4:1 AND B. THAT DURINGSAID SAPONIFICATION STEP AND THROUGHOUT THE ENTIRE PREPARATIVE PROCESSTHE SAPONIFICATION TEMPERATURE SHALL NOT EXCEED THE MELTING POINT OF THECALCIUM AND LITHIUM SOAPS FORMED DURING THE SAPONIFICATION PROCESS SAIDNON-MELT PROCESS CONSISTING ESSENTIALLY OF:
 1. ADMIXING FROM ABOUT 4.5PARTS BY WEIGHT TO 20 PARTS BY WEIGHT OF THE SAPONIFIABLE FATTY MATERIALWITH FORM ABOUT 0.1 TO 1.6 PARTS BY WEIGHT OF CALCIUM HYDROXIDE AND FROMABOUT 0.1 TO 1.3 PARTS BY WEIGHT OF BASIC LITHIUM HYDROXIDE MATERIALS INTHE PRESENCE OF SUFFICIENT MINERAL OIL TO MAINTAIN THE RATIO OF SAIDMINERAL OIL TO SAID FATTY MATERIALS RANGING FROM 2:1 TO 4:1, AND TO FORMA SAPONIFICATION MIXTURE;
 2. HEATING SAID SAPONIFICATION MIXTURE UP TOBUT NOT EXCEEDING THE MELTING POINT OF THE CALCIUM AND LITHIUM SOAPUNTIL THE CC ALCIUM AND LITHIUM SOAP ARE FORMED;
 2. The process of claim1 wherein the saponification temperature ranges from 230*F to 293*F. 2.heating said saponification mixture up to but not exceeding the meltingpoint of the calcium and lithium soap until the calcium and lithium soapare formed;
 3. adding from 5.0 to 0.1 parts by weight of a copolymer ofpolyoxyethylene and poly-1,2-oxypropylene having a molecular weight offrom about 2300 to 2500 to said heated saponification mixture, and 3.The process of claim 1 wherein the saponifiable material is stearicacid.
 3. ADDING FORM 5.0 TO 0.1 PARTS BY WEIGHT OF A COPOLYMER OFPOLOXYETHYLENE AND POLY-1,2-OXYPROPYLENE HAVING A MOLECULAR WEIGHT OFFROM ABOUT 2300 TO 2500 TO SAID HEATED SAPONIFICATION MIXTURE, AND 4.The process of claim 1 wherein the saponifiable fatty material is12-hydroxystearic acid.
 4. adding to the heated mixture of mineral oil,calcium and lithium soaps from 7.0 to 0.5 parts by weight of grEaseadjuvants while maintaining the temperature of the saponificationmixture below the melting point of said lithium and calcium soap whileoptionally adding sufficient mineral oil to said saponification mixtureuntil a grease of the desired consistency having good lubricationproperties, good resistance to water and good appearance is produced. 4.ADDING TO THE HEATED MIXTURE OF MINERAL OIL, CALCIUM AND LITHIUM SOAPSFROM 7.0 TO 0.5 PARTS BY WEIGHT OF GREASE ADJUVANTS WHILE MAINTAININGTHE TEMPERATURE OF THE SAPONIFICATION MIXTURE BELOW THE MELTING POINT OFSAID LITHIUM AND CALCIUM SOAP WHILE OPTIONALLY ADDING SUFFICIENT MINERALOIL TO SAID SAPONIFICATION MIXTURE UNTIL A GREASE OF THE DESIREDCONSISTENCY HAVING GOOD LUBRICATION PROPERTIES, GOOD RESISTANCE TO WATERAND GOOD APPEARANCE IS PRODUCED.
 5. The process of claim 1 wherein thesaponifiable fatty material is a mixture of stearic acid and12-hydroxystearic acid.